US2245640A

US2245640A - Method of molding paraffin wax

Info

Publication number: US2245640A
Application number: US73604A
Authority: US
Inventors: Beattie Robert
Original assignee: TIDE WATER ASSOCIATED OIL COMP
Current assignee: TIDE WATER ASSOCIATED OIL Co; TIDE WATER ASSOCIATED OIL COMP
Priority date: 1936-04-10
Filing date: 1936-04-10
Publication date: 1941-06-17
Anticipated expiration: 1958-06-17

Description

June 17, 1941. R. BEATTIE METHOD OF MOLDING PARAFFIN WAX Fiied April 10, 193s iA1 Troia/@hy Patented June 17, 1941 Mscrnon oF MODDING PARAFFIN WAX Robert Beattie, Plainfield, kN. J., assignor, by mesne assignments, of three-fourths to Tide Water Associated Oil Company, New York, N. Y., a corporation of Delaware Application april 1o, 1936, serial No. 73,604

6 Claims.

This invention relates to the forming of wax into bodies of defined shape. In its broader and more general aspects,the invention" is concerned with the formation of shaped` Wax .bodies (such as bars, cakes, and the like) by a continuous process enabling flexible control Vof production and-economical manufacture. More particularly, the invention provides an improved method of forming solid shaped bodies of parafn wax by an extrusion operation. Y

The present invention, while generally applicable to the formation of Wax bodies or articles of various shapes and for various-purposes, has particular utility in the refinery production of paramn wax in cake form for shipment to industrial consumers. Parafii-n wax production is an important adjunct of the petroleum industry, and, since the major industrial-and commercial requirements are for refined wax of relatively high melting point (say, from 120 F. to 135 F. or even higher), it has long been the practice to form such wax into cakes or bars of standard size to facilitate packing, shipping, storing and handling this product.

This expedient is quite feasible because of the relatively high melting points of the waxes in question, there being little or no tendency for the cakes to soften and deform unduly under climatic conditions ordinarily encountered. As a convenience for industrial consumers, the use or handling of wax in cake form has, in fact, proved so satisfactory that cake forming has become, of necessity, a usual and required final step in the production of parailin wax at the refinery. To this end, the refined wax-is stored according to grade (i. e., melting point) in tanks from which it is fed, as required, in molten condition to a plurality of water-cooled molds in which the molten wax cools and hardens to form cakes, ordinarily conforming to a standard weightof eleven (11) pounds, and measuring 18 to 19 inches in length, -12 inches in width, and 11/2 inches thick.

The formation of Waxor bars by a simple casting operation in thismanner is universal in the trade and has so been fora considerable number of years. Parafiln wax is a material of definitely crystalline nature and, therefore, is inherently well adapted to be formed into cakes or other dened shape by a casting operation. There are, however, certain fundamental defects in this traditional methodV of cake forming which interfere seriously with the efiiciency and economy of the operation.. The casting method with a slow Lcooling material such as wax, necessarily imposesfbatch'operation with its attendant difficulties anddrawbacks in the form of the unduly large number of units which must be maintained to meet varying. market demands, the high initial investment which this implies, the excessive space and time requirements, especially for non-productive portions of the operation such as set-up and cleaning periods, and the like. These and other factors, both major and minor, have long commanded the attention of those skilled in the art, and many efortshave been made to nd ways and means ofr improving the process but Without material success. The desirability of providing a new methodv of wax cake forming, which Willbe free of Ymany of the defects now encountered, is evident.

According to. the present invention, the foregoing diiculties are obviated by the discovery that the formationofV shaped wax bodies may be effected in anV extrusion operation, and by the development therefrom of a novel process of wax bodyforming. As.` will appear more fully hereinafter, the inventionv thus attains by this discovery, and .the improved process based thereon, desirable objects and advantages arising from continuous operation, flexible production control, operating economy,.and low initial investment 'for equipmentas compared withY the older method.

In the'accompanying drawings there is shown, for purposes of illustration, apparatus adapted for use in facilitating ,the operation of the process of the invention. l

In the drawing, in which like reference characters denote like parts- Figure I depicts. in generally diagrammatic form, an arrangement of apparatus adapted for wax body forming in accordance with present invention; and y Figure 1I depicts, in diagrammatic layout, an alternative embodiment which the extrusion apparatus of Figure I conveniently may take i practice. f

The wax body forming process of the present invention may be regarded generally as comprising the main steps of (a) preparing va quantity or mass of unformed rened wax for body forming treatment; (b) extruding such wax supply continuously through a suitable die structure to form an extended continuous strip of uniform pre-determined cross-section; (c) continuously conditioning such strip as received through and from the die structure to avoid deformation; (d) severing the same transversely at spaced predetermined intervals along the length thereof to form individual unitary wax bodies .comprising the desired wax cake product; and continuously maintaining such correlation of operating conditions, for example, temperature of the wax feed and operating temperatures maintained in the extrusion stage, with respect to the physical characteristics of wax under treatment, as to ensure continuity of operation and quality of product. The process further may include such secondary and supporting steps and refinements as pretreatment of the wax supply to condition the same for the extrusion operation, two-stage eX- trusion, and intermediate de-aeration of the Wax in process as by the inclusion of an intermediate vacuum conditioning step in the general process.

It has been determined that the successful adaptation of the principle of extrusion to the formation of wax bodies of defined shape necessitates (possibly because of the essentially crystalline nature of the material) -a careful observance of temperature conditions at the several stages of the forming process as herein disclosed. Neglect of this factor apparently is fatal to the successful operation of the method and to the production of a satisfactory wax cake product. The precise optimum temperatures to be maintained in the wax feed supply and during the forming operation may, for purposes of practicability, be determined as a relatively narrow range, but undue deviation from the limits of such temperature range should be avoided.

It has been found, in semi-plant scale operation with waxes of different melting point, as, for example, 120 F., 125 F., 130 F., and 135 F., that the feed and the operating temperatures or temperature ranges vary for different grades of Wax. Consequently, it is important to maintain. a certain correlation between the physical properties of a given grade of wax, as evidenced most feasibly by its melting point, and the temperature conditions maintained in the several stages of the process.

Exploratory operation of the process under widely Varying conditions has demonstrated that, as the feed wax enters the body forming means provided, its temperature should be suiciently high to ensure complete merging of the several wax particles or crystal agglomerates into a substantially homogeneous mass during the body forming operation. At the same time, it is necessary to avoid a temperature approaching the melting point of the Wax in process so closely as to interfere with continuous and substantially uniform feed to and through the extrusion unit, and with the formation of a firm undeformed wax body. lThus, the initial operating control in the process of the invention is concerned with the temperature maintained in the wax feed supply as it is delivered to the body forming operation. This is a unitary control in that, for a wax supply of given melting point, the same pre-determined feed temperature or temperature range should be maintained-and for different Wax supplies of different grades or melting points, other feed temperatures or temperature ranges obtain in accordance with the prescribed melting pointfeed temperature correlation. In the practice of the invention, this initial control has been found to be essential to as a multiple control, as compared with the unitary nature of the initial or wax feed temperature control, in that the required temperature conditions for a given grade or melting point Wax vary control.

in different stages of the body forming operation. That is to say, during the rst stage of the body forming or extrusion operation certain temperature conditions should prevail, at another subsequent stage different temperature conditions are called for, and at the final stage as the formed body is emitted still other temperature conditions are maintained.

The operating control in the body forming or extrusion operation is of importance to proper operation and to production of a satisfactory wax cake product. As indicated, this control is multiple in nature as compared with the unitary character of the initial or feed supply temperature It diers further, in that the initial control is concerned with the average temperature throughout the body or mass of the wax feed; while the secondary or multiple control is concerned with the temperature of the outer layer or surface of the wax mass passing through the body forming operation.

The desirability of so controlling the temperature of the wax feeding to the body forming operation of the process naturally influences to some extent the form in which the wax feed is most advantageously supplied for the extrusion treatment. The Wax feed may, of course, be supplied in a variety of Ways as, for example, in the form of lumps, pieces, bars, masses, and the like, whether or not uniformly sized. It has been found quite convenient, however, to supply the wax feed in relatively comminuted form, as in small flakes or chips, Which has the important advantage of facilitating the establishing and maintaining of the wax feed temperature within the required range. This method of preparing the Wax feed likewise adds further flexibility to the process as a whole, since changes in the Wax feed temperature in accordance with changes in the grades of wax being processed are more readily effected than might otherwise be the case.

If4 desired, a conventional type of wax flaking or chipping apparatus, generally available in most refineries, may be utilized for preparing the Wax supply in the desired form for cake forming treatment. As ordinarily arranged and operated, this apparatus comprises a large cylindrical drum so disposed above a shallow pan or tray containing molten Wax that the lower portion of the drum is continually submerged in the bath of melted wax. The surface of the drum is maintained at desired low temperatures, as by cooling water supplied internally thereto, and, as it rotates continuously, a thin film or coating of Wax is picked up and hardens on the exposed areas of the outer drum surface. At a suitable point in the rotation of the drum this lm or coating comes in contact with a shearing blade disposed parallel to the axis of the drum and in such relation to the surface thereof that, during the continued rotation of the drum, a wax coating is continuously and completely scraped off to fall in chip'or ake form to a suitable receiver.

, It will be understood, of course, that such other arrangements for preparing the wax supply in chip or flake form as may suggest themselves may be used, and further, that the wax feed may be in `units conventionely adaptable for use in carrying out the process of the present invention. Herein,

agresse-4st posedassto surround the forward portion-of the 'a wax aker of substantial conventionaldesig-n, generally designated Iat IIl, is disposedi in elevatedl relation to an extrusion unit III, arranged to re- .ceive'wax chipsv or flakes under gravityI feed. through a chute I2' from the flaker II);

As shown, the wax ilaker I includes-the usual drum I3, wax pan I4,' and scraper'blade I5; but it has been found convenient, in the practice of'v the presentv invention, to modify slightly the cus tomary relation ofv certain of the parts. Thus, it will -be noted that the drum I3'is so' positioned above the pan I4 that the lowermost portion'of the drum surface is spacedA somewhat from'the level `of the moltenwax. With this arrangement; an air spray line I6 is provided, beneath the levely of the waxin the pan and running lengthwiseof? the drum I3, which serves to transfer 'the molten wax in regulable quantityfrom thefpan I4` to the cooled surface of the'drum I3. Thepan I4 like-l wise may be .provided Withsteamcoils I1 forfmain'- taining the wax in the desired molten state. This modicationof the' conventionall Waxflaker setup thus enables accurate regulationl and control of such factors as amount of wax fed per unit` of time, temperature of .wax so fed, and occludedair content of the resulting flakes or chips as delivered from the flaker to the extrusionunit I I.

'Ihe wax flaker unit. I0 may, of course, be utilized with its customary arrangement of partsas previously outlinedand as generally familiar in the art; but in such instances there'fmay be encountered the disadvantage of having available a `relatively smaller degree of controlv over the rate at which the wax is supplied to the surface of the drum I3 from the pan I4'. This defect may be overcome to some extent by employing the conventional flaker assembly together with an air spray line as hereinbefore described. In any event, it is to be clearly understood that there is contemplated-a reasonable freedom of choice-in regard to this step in the integrated operation of the invention.

The extrusion unit II comprises generally a cylindrical barrel I8 defining; a laterally closed path of travel for the rwax feed which passes therethrough under pressure asfromv a screw I9 rotatably disposed within thesaid barrel. At its discharge end, the barrel I8 is provided With. a pre-forming section 2li, having tapering upper and lower walls, presenting successive rectangular cross-sections of constant width and diminishing in area to that of the die orifice proper` which accords with the transverse sectional dimensions of the cake to be formed. This section 2Ilfunctions to translate the combined rotary and-forward motion of the wax feed through the barrel I8 into substantially linear forward motion into and through a die section 2I abutting therestricted end of the pre-forming section 20.

The extended continuous strip of wax issuing from the die 2I herein is received-upon a series of rollers 22 arranged to support such strip without deformation in its continued travel away from the extrusion unit II to subsequent operations where it may be conditioned, severed, wrapped and packed.

As shown, the extrusion unit II is jacketed at suitable and desired sections. thereof to enable temperature regulation and control at the several stages of the forming operation. Herein, a jacket 23 of substantial length is disposed around the barrel I8 intermediate its length; while a jacket 25 quite short in longitudinal extent is disposed around the tip ordischarge end of the diesection` 2i'. Anl intermediate jacket 24is1so dis'- 75 pre-formingfsection 2B and the rearward'or receiving end portion of the die section 2|'. The said-

jackets

23, 24, and 25 are adapted to receive heat transmitting fluid, as for example, water or steam, orboth, from any convenient sourcesV Disposed' above the rollers 22 are a plurality of A sprays 21 through which cooling water from a manifold 28-is discharged upon the surfaceof thel extruding waxstrip or ribbon in order to set rmlythe outerl surface shell thereof. The said strip; after passing under the cooling water sprays 2'I; kmay'besubjected to air drying as by upper andlower air jets 29 arranged aboveand belowv the path of travel. Further drying of the formed wax body may be effected, if desired, by passingthe'same between felt pads 30 and 3|, arranged to .presslightly upon the upper and lower surfaces ofthe movingstrip or ribbon; and disposed within a Vacuum drying box 32.

Inoperatiomwith the aid of the apparatus depicted in Figure I and described as to its several cooperating units in the foregoing paragraphs, a supply of wax, say 130 F. melting point, is maintained in molten condition in the tray or pan I4 of the Wax'aker unit' I0, the steam coils I1 permittingv control of the fluidity and temperature of themelted wax; This wax then is transferred at desired rates to the cooled outer surface of tliedrumA I3 by means of the air spray line I6. The continuous rotation of the drum I3; by any convenient source of power, cooperating with rthe scraper blade I5' causes a supply of wax chipsor flakes to be delivered through the chute vI2 from the'flaker II) to the extrusion unitI I When operating upon r130" F. meltingy point wax; according to the instant body forming process, it has been found desirable to establish and maintain'the supply of wax to the extrusion unit within a temperature range of from F. to F; in order to obtain effective body forming operation'for the production of a smooth compact cake product free of deformation and satisfactory in appearance. With this, as well as other grades of wax, the molten wax supply to and in the flaker pan conveniently may be maintained ata temperature approximately 5 F. to 10 F. above the-melting point of the wax in question; and the desired Wax chip feedtemperature obtained by regulation and control of the'quantity ofA molten wax supplied tol the flaker drum, the temperature ofthe cooling water therewithin, andthe amount and temperature of the air spray through the line I6.

As a precautionary measure, when using a Wax aker-unit as described for the purpose of preparing the wax feed supply, the adjustment of the scraper blade I5 relative to the adjacent surface of the drum I3 should be checked occasionally to ensure the complete removal of the hardened wax coating continuously formed thereon. Otherwise, a thin permanent coating of wax; may build up on the outer surface of the drum and, by its insulating effect, interfere with the desired rate of cooling the molten wax continuously transferred to the said surface from the pan I4.

As'the Waxfeed passes into the receiving end of the extrusion' barrel I8l it is* pressed forward underpressure yby the screw'k |95 To ensure both a substantial co-efcient of friction between thev inner surface of the barrel I8 and the Wax carried by the screw I9. Consequently, cooling water is passed continuously through the jacket 23, and it has been determined that satisfactory operation results when this cooling water is maintained at a temperature of from 45 F. to 55 F. both for wax of 130 F. melting point and for other grades both higher and lower in melting point. 'I'he temperature of the cooling` water flowing through the jacket 23 may be quite some lower in temperature than 45 F., but temperatures greatly in excess of 55 F. are to be avoided.

When the wax feed finally passes from the barrel I8, through the pre-forming section 20, into the section 2|, it is beneficial to maintain the side walls of the unit at progressively higher temperatures than the walls of the barrel I 8. Here, the co-efIicient of friction between the wax and the inner walls of the die should be relatively low in order to provide for smooth passage of the wax body therethrough with gradually diminishing resistance in order to maintain substantially uniform linear forward velocity throughout the body of the wax. Hence, it has been found advantageous to maintain a uid temperature in the jacket 24 of the order 90 F. to 100 F. while that in the nal jacket 25 advantageously may be held at or somewhat above the melting point of the wax being processed.

In this illustrative operation, the body forming method of the invention was so conducted as to produce an extruded wax strip at the rate of approximately 40 linear inches per minute, the formed body or strip having a width of approximately 12 inches and a thickness of approximately 11/2 inches.

The continuous body or strip of formed wax extruding from the die section 2| is, as before explained, conveniently received upon rollers 22; and, during its passage thereover, cooling water is sprayed upon the surface of the wax body to immediately cool and set the same to retain the smooth even surface imparted thereto by the nal action of the die 2| and cooperating jacket 25. Following this treatment the extended body of wax may be air blown and passed between the absorbing surfaces of the vacuumized felt layers or pads 30 and 3| for drying. The wax strip then is ready for severing at spacedintervals into cakes of uniform length which may subsequently be wrapped, packaged, and stored in any desired manner.

YAs before indicated, it is important to the satisfactory production of wax cakes by the present process that the temperature of the wax as fed to the body forming or extrusion operation be established and maintained within a pre-determined range suitably correlated to the melting point of the wax being processed. In the foregoing description of the process in connection with the processing of 130 F. melting point wax, a temperature range of from 85 F. ot 95 F. was shown to be a suitable one within which to maintain the temperature of the wax chips as fed to the extrusion unit. In other words, when forming shaped wax bodies from 130 F. melting point wax, the temperature of the wax chip feed should be established and maintained at not substantially less than 35 F. nor substantially more than 45 F. below the melting point of this particular grade of wax. Under the prescribed coruniform forward travel and continuous mergingA istics, a continuous. uniformly sized stripl was obtainedv which. uponk severing at uniformly spaced intervals along the length thereof, produced cakesy comparing very favorably in quality with those produced in the conventional casting operationas ordinarily employed in the art.

It is not possible to set forth an exact mathematical formula for calculating, fora given grade of wax, the precise differential to be established and maintained between the operating temperature of the `wax feed andthe melting point of the particular wax in question. Thus, as aforeindicated, for 130 F. melting point wax a temperature differential within the range of 35 to 45 F. has given satisfactory results in large scale operation, while with different grades of wax (i. e., higher or lower melting points), other temperature differentials obtain. In general, it has been observed that the lower melting point waxes are best processed under conditions such that a larger differential exists than is necessary for waxes of higher melting point. For example, satisfactory cakes were obtained when extruding F. melting point wax under a differential of from 40 F. to 50 F. maintained between the chip feed temperature and the wax melting point. On the other hand, wax of 135 F. melting point was Vprocessed to good quality cake product with an operatilng temperature differential in range of 35 F. to 40 F; while 125 F. melting point wax formed well in the instant operation under substantially the same( temperature correlation as hereinbefore indicated for F. melting point wax. In all cases, however, the principle of suitably correlating the wax feed temperature to the melting point of the wax being processed is effective and apparently necessary to operation of the method. With this principle established as an important operating factor, the adaptation of the invention to forming shaped wanv bodies from waxes other than those particularly enumerated herein will be readily achieved by those skilled in `the art to whom the teachings of this speciflcation are made available.

As to the temperature conditions maintained, by means of the jacket 24, at the intermediate stage of the body forming operation, the necessary correlation involves both the melting point of the wax in process and the rate of passage through the body i forming operation. At this intermediate stage, defined by the last portion of the .pre-forming section 20 and the first portion of the die. section 2|, the operating temperature should be so' correlated to the melting point of the wax: and to the rate of forward motion as to approach a condition of maximum plasticity of the surface layer of wax adjacent the inner wall surface of the unit without causing melting of this wax surface or layer. Thus, for different grades or melting point waxes, the temperature of the fluid passing through the jacket 24 will be `adjusted in relation both to the melting point of the wax-and to its rate of forward movement.

In Iikemaner, the temperature of the uid passing through the final jacket 25, disposed at the discharge end of the die piece' 2|, will be determined in correlative relations both to the .melting point of the wax in process and to the rate of wax body passage or discharge; and will be so adjusted as'to induce an incipient fusion of the very outer surface of the formed wax body at the point of discharge without affecting the rigidity' ofthe body itself. By this practice, the

relation of operating conditions to wax character- 7 5 emergence of the formed wax body is rendered smooth and unimpeded, thereby avoidingfdefor'- mation or surface roughness. ff

The extruded wax bodies or cakes formed by the practice of the present invention arecharacterized by a structure which presents incrosssection a series of concentric lamina-tions or strata. This structure apparently is responsible for the enhanced strength, both in longitudinal and in transverse section, which these cakes exhibit in comparative tests with conventional cakes of the same melting point wax produced'by the customary moulding or casting method. The extruded cakes may be substantially the same in density as the moulded cakesfor may run somewhat lighter,ldepending upon the amount of occluded airthat is permitted to be 'entrained with the wax chips during the body forming operation. 'vIhe amountr of air present in the extruded cakes likewise may affect the surface appearance thereof, and it is possible, by regulation of the'\ of the inner wall of said section 2| may be maintained at somewhat above the melting point'of the wax in process, causing a thin layer ofwax at the outer surface of the formed body tc'melt,r

which, upon immediate chilling as it emerges onto the rollers 22 and beneath the cooling water sprays 21, produces a smooth snow-white surface ap` pearance similar to that presented by the vwax cakes formed in a molding or casting operation. Experimental operation has demonstrated that this effect can readily be produced by the indicated procedure without deleterious effect upon other desired characteristicsof the extruded cake, such as enhanced strength, uniform cross-sectional dimension, and the like.

A further embodiment of the present invention may be carried out with an arrangement of apparatus such as that shown diagrammatically in Figure II of the accompanying drawing. In this embodiment, provision is made for conditioning the wax feed at an intermediate point in the extrusion stage of the process; and, when operated according to Figure II as hereinbelow described, the process might aptly be considered as involving a two-stage extrusion operation.

The wax feed supply in this embodiment, as in that described in connection with Figure I, may be initially prepared in chip or flake form; and Figure II therefore does not include the wax aker unit I0, a duplicated showing of this portion of the apparatus being unnecessary to an understanding of the features of the invention now to be presented.

Referring now more particularly to Figure Il, there is there shown a Wax body forming unit comprising generally a conditioning section and a forming section, the latter being in all essential respects identical with the extrusion unit II of Figure I. 'Ihe conditioning section, indicated generally at 33 provides, in effect, a first extrusion operation, and has a horizontally disposed cylindrical barrel or chamber 34, adapted to receive a wax feed supply, as in chip or flake form. Rotatably mounted within the chamber 34 is a screw 35, the shaft of which comprises a rearward extension of the shaft of screw I9 in unit Il and by means of which the wax supply is passed forwardly under pressure. At the discharge end of the barrel 34 there is fixed a perforated plate 36, through the openings in which the wax feed is forced or extruded to emerge asa plurality of relatively small ribbons 'or'v pencil-like sections, thereby presenting at emergence a large exposed surface area relative -to'the total'mass. 'Ihe ribbons of wax thus extruded through the plate 36 are received in a confined space or chamber 31 which is arranged to be evacuated by any convenient means indicated diagrammatically at 38. At the far end of the chamber 31 is attached an extrusion unit I I similar in all respects to that shown in Figure I and previously described in connection therewith. For convenience of assembly and operation, the extrudving screws 35 and I9 respectively may be provided with a common shaft as shown, this an arrangement permitting the use of common drive mechanismv (not shown) for the two extrusion units. The screw 35 operating in the first extrusion unit 33 is,` of course, discontinued just before the perforated plate 36; while the screw I 9 in the second extrusion unit II has its first turn spaced from Jhe opposite or discharge side of said plate. 'Ihe wax; emerging in ribbon-like or pencil-like form through the plurality of openings in the perforated plate 36, thus passes through the evacuated chamber 31 and feeds directly to the unit I I, whereit is subjected to the final body forming treatment hereinbefore set forth.

f When practicing the invention with a form of lapparatus such as that just described, a supply of wax chips or flakes passes from a flaker unit I ll by gravity through a chute I 2 to the feed end of thev barrel 34 of the preliminary extruder 33. Here,. the wax chips are pressed forwardly by the continuous rotation of the screw 35 and forced or extruded through the. perforated plate 36 into the vevacuated chamber 31. y As previously indicated, the wax emerging through the plate 36 in the form of a plurality of thin pencils or ribbons, `presents a very large area of exposed suru face relative to the mass; and thus is readily responsive to the de-aerating action of evacuating means 38 operatively associated with the chamber 31. Whatever means is selected to create the desired vacuum advantageously may include regulatory control for varying the degree of vacuum imposed upon the said chamber in order to enhance the flexibility of the operation, as, for example, to meet possible variations in the amount of occluded air carried by the wax, degree of deaeration desired, variations in the wax feed rate, and the like. I1; will be understood, of course, that the particular evacuating means selected forms no part of the present invention, and since many conventional and well-known devices are readily available, it is deemed unnecessary to include here any detailed showing or description of a specific illustrative device.

In operation with this embodiment of the invention, as with that rst described, it will be understood that the prescribed operating controls and correlations must be observed.

I claim:

1. In a method of forming paraffin wax into bodies of defined shape by continuously extruding a supply of wax in relatively comminuted solidified state through suitably dimensioned body forming means, the improvement which comprises maintaining, during the body forming operation, a differential between the wax supply temperature and the melting point of the wax of not substantially more than lty (50) nor substantially less than thirty (30) degrees Fahrenheit. Y

2. In al method of forming paraffin wax into bodies of defined shape by continuously extruding a supply of` wax in relatively comminuted solidified state through suitably dimensioned body forming means, Ythe improvement which comprises maintaining, during the body forming operation, a diiferential between the wax supply temperature and the melting point of the wax of not substantially more than fifty nor substantially less than thirty degrees Fahrenheit, the differential selected for any given melting point wax being of the higher order for lower melting point waxes and of the lower order for higher melting point waxes.

3. In a method of forming paraflin wax into bodies of defined shape, by continuously feeding a supply of wax in solidified state, maintained at a temperature substantially below the melting point thereof, to and through a relatively elongated chamber of restricted coss-section terminating in body forming and shape defining means operatively yassociated therewith, the improvement which comprises maintaining the Walls of said chamber at a temperature below that of said wax supply passing therethrough, and maintaining said means at a temperature well above that of said chamber walls. l

4. The method of forming paraiiin wax into bodies of defined shape, which comprises continuously feeding a supply of wax in relatively comminuted solidiiied state, maintained at a temperature substantiallyv below the melting point thereof but so correlated thereto that body form.

ing conditions obtain during the body forming operation, to and through a relatively elongated chamber of restricted cross-section terminating in body forming and shape defining means operatively associated therewith, maintaining the walls oi said chamber at a temperature within the range of forty-ve to fifty-live degrees Fahrenheit, and maintaining successive zones in said means at successively increasing. temperatures. the zone of said means adjacent the point of emergence of said wax being at a temperature substantially that of the melting point of the wax passing therethrough.

5. The method of forming parain wax having a melting point not substantially less than 120 F. into bodies of dened shape, which comprises continuously feeding a supply of wax in relatively comminuted solidied state, maintained at a temperature which is at least 30 F. below the melting point of the wax treated, to and through a relativel'y elongated chamber of restricted cross-section terminating in body forming and shape dening means operatively associated therewith, maintaining the walls of rsaid chamber at a temperature within the range of to 55 F., and maintaining successive zones in said means at successively increasing temperatures, the zone of said means adjacent the point of emergence of said wax being at a temperature substantially that of the melting point of the wax passing therethrough.

6. The method of forming parain wax having a melting point not substantially less than 120 F. into bodies of defined shape, which comprises continuously feeding a supply of wax in relatively comminuted solidified state, maintained at a temperature which is at least 30 F. below the melting point of .the wax treated, to and through a relatively elongated chamber of restricted cross-section terminating in body forming and shape defining means operatively associated therewith, maintaining the walls of said chamber at a temperature within the range of 45 to 55 F., and maintaining successive zones in said means at successively increasing temperatures, the zone of said means adjacent the point of emergence of Vsaid wax being at a temperature substantially that of the melting point of the Wax passing therethrough,

the zone intermediate said chamber and the point of emergence of said wax being. maintained at a temperature within the range of to 100 F.

ROBERT BEA'rriE.